#!/bin/bash

Create () {

	#Authors

	declare -i n=1
	array=()

	while :
	do
		if [ "$n" -ge "2" ]; then
			echo -n "Do you have more authors?[Yes/No]:"
			read result
			if [ "$result" != "Yes" ]; then
				break;
			fi
		fi

		echo -n "Please enter a name of author$n:"
		read author
		echo $author
		if [ "$author" == "" ]; then
 		  	 echo "Author input is incorrect"
 		else
			array[$n]=$author
   		n=$(( n + 1 ))
  		fi
	done

	printf "\nAuthors:\n"
	for item in ${array[*]}
	do
	    printf "   %s\n" $item
	done

	#Titles
	while :
	do
		echo -n "Please enter a title of a book: "
		read title
		if [ "$title" == "" ]; then
			echo "Title is incorrect. Please try again"
		else
			break;
		fi
	done

	printf "\nTitle:\n"
	printf "   %s\n" $title

	#Pages
	while :
	do
		echo -n "Please enter a number of pages: "
		read pages
		if [ "$pages" != "" ] && [ $pages -eq $pages 2>/dev/null ] && [ $pages -gt "0" ]; then
			break
		else
			echo "Please write a correct number of pages"
		fi
	done

	printf "\nNumber of pages:\n"
	printf "   %s\n" $pages

	#Year
	while :
	do
		echo -n "Please enter a year of book's release: "
		read year
		currentYear=$(date +'%Y')
		if [ "$year" != "" ] && [ $year -eq $year 2>/dev/null ] && [ $year -gt "1000" ] && [ $year -le $currentYear ]; then
			break
		else
			echo "Please write a correct year"
		fi
	done

	printf "\nYear:\n"
	printf "   %s\n" $year

	#Other values

	keys=()
	values=()
	declare -i in=0

	while :
	do
		echo -n "Do you want something else(key: value)?[Yes/No]:"
		read result
			if [ "$result" != "Yes" ]; then
			break
		fi

		while :
		do
			echo -n "Please enter a key: "
			read key
			if [ "$key" == "" ]; then
				echo "Key is incorrect. Please try again"
			else
				keys[in]=$key
				break
			fi
		done

		while :
		do
			echo -n "Please enter a value: "
			read value
			if [ "$value" == "" ]; then
				echo "Value is incorrect. Please try again"
			else
				values[$in]=$value
				in=$(( in + 1 ))
				break;
			fi
		done
	done

	printf "\nKeys and values:\n"

	if [[ ${!values[*]} != "0" ]]; then
		for index in ${!values[*]}
		do
			printf "%s: %s\n" ${keys[$index]} ${values[$index]}
		done
	fi

	#Creating a record

	number=1

	while :
	do
		recordName="record$number.txt"
		if [ -f "$recordName" ]; then
			number=$(( number + 1))
		else
			break;
		fi
	done

	#Authors
	for item in ${array[*]}
	do
		echo "author: $item" >> $recordName
	done

	#Titles
	echo "title: $title" >> $recordName

	#Pages
	echo "pages: $pages" >> $recordName

	#Year
	echo "year: $year" >> $recordName

	#Other
	for index in ${!values[*]}
	do
		echo "${keys[$index]}: ${values[$index]}" >> $recordName
	done

	echo "Record is successfully created. Name: $recordName"
}

Search () {

	author=""
	title=""

	echo "Do you want to search by author?[Yes/No]"
	read result
	if [ "$result" == "Yes" ]; then
		while :
		do
			echo -n "Please enter an author of a book: "
			read author
			if [ "$author" == "" ]; then
				echo "Author name is incorrect. Please try again"
			else
				break;
			fi
		done
	fi

	echo "Do you want to search by title?[Yes/No]"
	read result
	if [ "$result" == "Yes" ]; then
		while :
		do
			echo -n "Please enter an title of a book: "
			read title
			if [ "$title" == "" ]; then
				echo "Title name is incorrect. Please try again"
			else
				break;
			fi
		done
	fi

	found="false"
	printf "\n"

	for i in record*.txt;
	do
		if [ "$author" != "" ]; then
  			result1=`awk '$1 == "author" && $2 == "'"$author"'" {n++}END{print n}' FS=": "  $i`

			if [ "$title" == "" ] && [ "$result1" != "" ]; then
				echo "Record with author $author found. Name: $i"
				found="true"
			fi
		fi

		if [ "$title" != "" ]; then
  			result2=`awk '$1 == "title" && $2 == "'"$title"'" {n++}END{print n}' FS=": "  $i`
			echo $result2;
			if [ "$result2" != "" ]; then
				if [ "$author" != "" ] && [ "$result1" != "" ]; then
					echo "Record with author $author and title $title found. Name: $i"
					found="true"
				else
					echo "Record with title $title found. Name: $i"
					found="true"
				fi
			fi
		fi
	done


	if [ "$author" == "" ] && [ "$title" == "" ]; then
		printf "No input. Impossible to search.\n"
	elif [ "$found" == "false" ]; then
		printf "\nNo result. Nothing found\n"
	fi
}

Delete () {
	while :
	do
		echo -n "Please enter a name of record you want to delete: "
		read record
		if [ "$record" == "" ]; then
			echo "Record name is incorrect. Please try again"
		else
			break;
		fi
	done

	if [ -f "$record" ]; then
		rm "$record"
		echo "Record $record was successfully deleted"
	else
		echo "No record with name $record was found"
	fi
}

#Main
if [ "$1" == "" ]; then
   	echo "Parameter is empty. Allowed parameters: create, delete, search"
elif [ "$1" == "create" ]; then
	Create
elif [ "$1" == "delete" ]; then
    	Delete
elif [ "$1" == "search" ]; then
	Search
fi